JP2016204930A - Back pack blast machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set a barycentric position of a back pack blast machine so that an operator can easily use the back pack blast machine.SOLUTION: The back pack blast machine comprises: a back pack frame having at least a back plate part 12 that fits along a back of an operator and allowing the operator to lift the back plate part 12 onto his or her back by a shoulder strap 13; a vortex volute case 21, which is mounted on the back pack frame behind the back plate part 12 and centered in a direction intersecting with a plane direction of the back plate part 12; a centrifugal fan 22, which is rotatably supported in the volute case 21; an electric motor 23, which is installed on the volute case 21 and rotates the centrifugal fan 22; and a battery pack 40, which is installed on the back pack frame and feeds power to the electric motor 23. A barycenter G viewed from behind is disposed below a rotary central shaft of the centrifugal fan 22, and the barycenter G viewed from the side is disposed at a position anterior to a rear end position of the volute case 21.SELECTED DRAWING: Figure 2

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backpack-type blower working machine used for cleaning work such as fallen leaves, and more particularly to a backpack-type blower working machine in which a worker carries out a cleaning work with a backpack frame mounted with a volute case, a centrifugal fan, and an electric motor.

  Patent Document 1 discloses a back blower that is an embodiment of a back blower working machine, and this back blower has an L-shaped back frame carried by an operator, and a volute case mounted on the back frame. And a centrifugal fan rotatably provided in the volute case, an electric motor which is assembled to the rear side of the volute and rotates the centrifugal fan, and a battery attached to the lower surface of the back frame. In this back blower, the centrifugal fan in the volute case is rotated by an electric motor driven by the power supply of the battery, and the air sucked into the volute by the rotation of the centrifugal fan is ejected from the outlet of the volute. Yes.

US Patent No. 6006400

  In the back blower of Patent Document 1, by using an electric motor as a drive source for rotating a centrifugal fan, noise reduction can be realized as compared with a case where an engine of an internal combustion engine is used as a drive source. However, in the back blower of Patent Document 1, a large electric motor is attached to the rear side of the volute, and a large battery is attached to the middle part in the front-rear direction of the lower surface of the back frame. The position of the center of gravity of the blower was behind the middle part in the front-rear direction. For this reason, when the back frame of the back blower is used on the back, the position of the center of gravity is at the rear, so that the operator is likely to fall back and the back blower is difficult to use. An object of the present invention is to provide a backpack type blower working machine set so as to have a center of gravity that is easy for an operator to use.

  In order to solve the above-mentioned problems, the present invention has a back frame that has at least a back plate portion along the operator's back, and the back plate portion is supported on the operator's back by a shoulder strap, and a back plate portion of the back plate portion. Mounted on the back frame on the back side, assembled in a volute with a spiral volute case centered on the direction intersecting the plane direction of the back plate, a centrifugal fan rotatably supported in the volute case, and It has an electric motor that rotates the centrifugal fan and a battery pack that is attached to the back frame and feeds the electric motor, and the center of gravity when viewed from the rear is located below the rotation center axis of the centrifugal fan, It is intended to provide a backpack type blower working machine characterized in that the center of gravity when viewed from above is arranged in front of the rear end position of the volute case.

  In the back-fitted blower working machine configured as described above, the center of gravity when viewed from the rear is disposed below the rotation center axis of the centrifugal fan, and the center of gravity when viewed from the side is the rear end of the volute case. Since it was arranged in front of the position, it was difficult for the operator to fall down to the rear side even when carrying the back frame, making it easy to use the back type blower working machine. In this case, it is preferable that the center of gravity when viewed from the side is arranged in front of the center in the front-rear direction of the volute case, and even if the operator carries the back frame, the back side is more unlikely to fall down. This made it possible to use the backpack type blower working machine more easily.

  In the backpack-type blower working machine configured as described above, the backpack frame preferably includes a pedestal portion extending rearward from the lower end portion of the back plate portion, and the battery pack is preferably attached to the pedestal portion. In this case, the center of gravity of the back fan can be lowered further, and the operator can stably carry the back frame.

It is a side view of the back type blower of 1st Embodiment of the back carrying type air blower of this invention. FIG. 2 is a longitudinal sectional view of a center position in the left-right direction (position of a rotation shaft of a prime mover) in FIG. 1. It is a rear view of the state which removed the cover of FIG. It is a side view of the back blower of a 2nd embodiment. FIG. 5 is a longitudinal sectional view of a center position in the left-right direction in FIG. 4 (position of a rotation shaft of a prime mover). It is a rear view of the state which removed the cover of FIG. It is the left view (a) of 3rd Embodiment, and is a rear view (b). FIG. 8 is a longitudinal sectional view at a position of a rotation shaft of the prime mover of FIG. 7. It is the left view (a) of 4th Embodiment, and is a rear view (b). FIG. 10 is a longitudinal sectional view at the position of the rotation shaft of the prime mover of FIG. It is longitudinal direction sectional drawing in the position of the rotating shaft of the motor | power_engine of 5th Embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A backpack type blower that is an embodiment of a backpack type blower working machine of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
As shown in FIGS. 1 to 3, the back blower 10 according to the first embodiment includes a back frame 11 having at least a back plate portion 12 along the back of the operator, and a rear side of the back plate portion 12. A volute case 21 that is mounted on the back frame 11 and centered on a direction intersecting the plane direction of the back plate 12, a centrifugal fan 22 that is rotatably supported in the volute case 21, and the volute case 21. And an electric motor 23 that rotates the centrifugal fan 22 and a battery pack 40 that is attached to the back frame 11 and supplies power to the electric motor 23. In the back blower 10, the center of gravity G when viewed from the rear is disposed below the rotation center shaft 22 a of the centrifugal fan 22, and the center of gravity G when viewed from the side is the rear end position of the volute case 21. The main feature is that it is arranged on the front side. The backpack type blower 10 will be described in detail below.

  As shown in FIGS. 1 to 3, the back frame 11 is for carrying the air blowing unit 20 including the volute case 21, the centrifugal fan 22, and the electric motor 23. A battery pack 40 that supplies power to the electric motor 23 and a control device 41 that controls driving of the electric motor 23 and power supply from the battery pack 40 are mounted. The back frame 11 has a back plate portion 12 along the operator's back, and the back plate portion 12 is supported on the operator's back by a pair of left and right shoulder straps 13. The back frame 11 further includes a pedestal portion 14 that extends rearward from the lower end portion of the back plate portion 12 that stands in a substantially vertical direction along the operator's back. The back plate portion 12 of the back frame 11 is formed with a number of air intake ports 12a for taking air into the blower unit 20, and air for taking air into the blower unit 20 also at the front portion of the pedestal portion 14. An intake port 14a is formed.

  As shown in FIGS. 1 to 3, the blower unit 20 blows air from the blower port 21 c at the tip of the blower cylinder portion 21 b by rotating the centrifugal fan 22 in the volute case 21 by the electric motor 23. The volute case 21 has a spiral shape centering on a direction orthogonal (crossing) to the planar direction of the back plate portion 12. The volute case 21 is formed with an air inlet 21a on the rear side, and a cylindrical air blowing cylinder portion 21b which is a spiral outer tip portion is formed on the right side portion so as to extend outward, and the air blowing cylinder portion 21b. An air blowing port 21c is formed at the tip of the air. A blower pipe 30 is connected to the blower port 21c of the blower cylinder portion 21b of the volute case 21 in communication.

  A centrifugal fan 22 is rotatably provided in the volute case 21, and an electric motor 23 is attached to the front surface of the volute case 21. The centrifugal fan 22 is fixed to the rotating shaft (output shaft) 23 a of the electric motor 23 in the volute case 21. In this embodiment, the electric motor 23 employs an outer rotor type electric motor. The blower unit 20 is a unit in which the electric motor 23 is integrally assembled on the front surface of the volute case 21, and the centrifugal fan 22 is rotatably attached to the rotating shaft 23 a of the electric motor 23 in the volute case 21. It has become. The air blowing unit 20 is elastically supported by the coil spring 15 on the back plate 12 in a state where a mounting space for mounting a battery pack 40 and a control device 41 to be described later is provided on the upper surface of the pedestal 14 in a state where it is a single unit. Has been.

  As shown in FIG. 1, the blower pipe 30 connected to the blower opening 21 c of the volute case 21 includes an elbow pipe 31, a bellows-like flexible pipe 32 connected to the tip of the elbow pipe 31, and the flexible pipe 32. And a straight pipe 33 connected to the tip. The straight pipe 33 is provided with a grip 34 held by an operator, and the operator can operate the grip 34 by holding the grip 34 so that the front end opening of the blower pipe 30 faces a desired direction.

  As shown in FIGS. 2 and 3, four attachment portions 16 for attaching the battery pack 40 are arranged in the left-right direction on the rear upper surface of the pedestal portion 14 of the backpack frame 11. The battery pack 40 for supplying power to the electric motor 23 is detachably attached so as to be slidable in the front-rear direction. The battery pack 40 can be charged by a charger (not shown) in a state where it is removed from the mounting portion 16, and a battery pack 40 that can also be used as a power source for other electric gardening machines and electric tools is used.

  As shown in FIG. 2, a control device 41 is attached to the upper surface of the front portion of the pedestal portion 14 of the backpack frame 11, and the control device 41 controls the drive of the electric motor 23, and from the battery pack 40 to the electric motor. 23 power supply is controlled. As shown in FIGS. 1 and 2, the back frame 11 is provided with a cover 42 that covers the blower unit 20 and the control device 41.

  The operation of the backpack type blower 10 configured as described above will be described. When the operator carries the back frame 11 with the shoulder strap 13 on his / her shoulder and drives the electric motor 23 with power supplied from the battery pack 40, the centrifugal fan 22 rotates in the volute case 21. The air sucked into the volute case 21 from the air inlet 21a by the rotation of the centrifugal fan 22 is sent out from the blower port 21c to the blower pipe 30 and the air sent out to the blower pipe 30 is blown out from the front end opening to the ground. The operator grasps the grip 34 of the blower pipe 30 and rotates the front end opening of the straight pipe 33 in the left-right direction on the front side of the worker, thereby collecting the fallen leaves scattered widely on the ground on the front side of the worker. Can do.

  The back blower 10 configured as described above is configured to drive the electric motor 23 by feeding power from the battery pack 40. Therefore, the electric motor 23 and four (plural) battery packs are used as heavy objects on the back frame 11. 40 and must be installed. The applicant of the present application is easy to use and fatigue when the operator carries the back-type blower 10 on the back, depending on the mounting position of these heavy parts (electric motor 23, battery pack 40, etc.) in the back-side frame 11. I noticed a difference. In contrast, the applicant of the present application has found that when the center of gravity of the back blower 10 is as low as possible and close to the operator, the operator can easily use the back blower 10 and feel less tired. Based on this knowledge, as shown in FIGS. 2 and 3, in the back blower 10, the center of gravity G when viewed from the rear is disposed below the rotation center shaft 22 a of the centrifugal fan 22. If the center of gravity G when viewed from the side is arranged in front of the rear end position of the volute case 21, it is possible to realize various ease of use and less fatigue of the back blower 10. I was able to find it from the data. Furthermore, if the center of gravity G when viewed from the side is arranged in front of the center of the volute case 21 in the front-rear direction, it can be found from various data that a more remarkable effect can be obtained. .

  For this reason, in the back blower 10 configured as described above, the volute case 21 is erected so that the spiral central axis of the volute case 21 intersects the plane direction of the back plate portion 12. By disposing the rear portion 12 on the rear side, the length of the back frame 11 in the front-rear direction is shortened so that the position of the center of gravity is disposed as close as possible to the operator's back. Further, in this embodiment, by fixing the electric motor 23 to the front surface of the volute case 21, the electric motor 23, which is a heavy object, is arranged in front of the volute case 21, so that the electric motor 23 is as close to the operator as possible. I have to. Furthermore, in this embodiment, the battery pack 40 is attached to the upper surface of the pedestal portion 14 of the backpack frame 11 below the volute case 21. In this way, in the backpack type blower 10, the electric motor 23, which is a heavy object, is fixed to the front surface of the volute case 21 in a state where the volute case 21 is raised so as not to be bulky by shortening the length in the front-rear direction. By placing the heavy battery pack 40 below the volute case 21, the center of gravity G when viewed from the back of the back blower 10 is lower than the rotation center shaft 22 a of the centrifugal fan 22 as described above. The center of gravity G when viewed from the side is disposed in front of the rear end position of the volute case 21, particularly in this embodiment, the center of gravity G when viewed from the side is the front-rear direction of the volute case 21. It was made to arrange | position ahead of the center C of no. This prevents the shoulder strap 13 from being hung on the operator's shoulder so that the shoulder strap 13 is pulled to the rear side even when working with the shoulder-type blower 10 on the back, making it difficult for the operator to fall back and I was able to make it hard to get tired.

(Second Embodiment)
Next, the backpack type blower 10 of 2nd Embodiment is demonstrated using FIGS. In the back blower 10 of the second embodiment, the blower unit 20 is configured by two blower units of the first and second blower units 20A and 20B. The first blower unit 20A is disposed on the rear side of the back plate portion 12 of the backpack frame 11, and the second blower unit 20B is disposed on the rear side of the first blower unit 20A.

  As shown in FIGS. 4 to 6, the first blower unit 20A is configured such that the first electric motor 23A is integrally assembled to the rear surface of the first volute case 21A, and the first electric motor is disposed in the first volute case 21A. The central portion of the first centrifugal fan 22A (position where the rotation center shaft 22Aa is located) is rotatably attached to the rotation shaft (output shaft) 23Aa of 23A to form one unit. The first volute case 21 </ b> A has a spiral shape centering on a direction orthogonal (crossing) to the planar direction of the back plate portion 12. The first volute case 21A has an air inlet 21Aa formed on the front side, and a cylindrical air blowing portion 21Ab serving as a spiral outer tip is formed on the right side. Air blower 21Ac is formed in the tip of 21Ab.

  As shown in FIGS. 4 to 6, the second air blowing unit 20B is configured such that the second electric motor 23B is integrally assembled to the front surface of the second volute case 21B, and the second electric motor is disposed in the second volute case 21B. The central portion of the second centrifugal fan 22B (position where the rotation center shaft 22Ba is located) is rotatably attached to the rotation shaft (output shaft) 23Ba of 23B to form one unit. The second volute case 21 </ b> B has a spiral shape centering on a direction orthogonal (crossing) to the planar direction of the back plate portion 12. The second volute case 21B has an air inlet 21Ba formed on the rear side, and a cylindrical air blowing cylinder portion 21Bb serving as a spiral outer tip on the right side is formed extending outward. An air outlet 21Bc is formed at the tip of the portion 21Bb. A blower pipe 30 similar to that of the first embodiment is connected to the blower ports 21Ac and 21Bc of the first and second volute cases 21A and 21B so that the air sent out from them joins.

  As shown in FIG. 5, the first blower unit 20 </ b> A is elastically supported by the back frame 11 by fixing the volute case 21 </ b> A to the back plate portion 12 via the coil spring 15. The second air blowing unit 20B is elastically supported on the back frame 11 via the first air blowing unit 20A by fixing the second electric motor 23B to the first electric motor 23A of the first air blowing unit 20A. In this embodiment, the rotation shafts 23Aa and 23Ba of the first and second electric motors 23A and 23B are arranged coaxially.

  As shown in FIG. 6, four attachment portions 16 for attaching the battery pack 40 are arranged in the left-right direction on the rear upper surface of the pedestal portion 14 of the backpack frame 11, and these attachment portions 16 include an electric motor. A battery pack 40 for supplying power to the power supply 23 is detachably attached so as to be slidable in the front-rear direction. The battery pack 40 can be charged by a charger (not shown) in a removed state, and a battery pack 40 that can also be used as a power source for other electric gardening machines and electric tools is used.

  As shown in FIG. 5, a control device 41 is attached to the upper surface of the front portion of the pedestal portion 14 of the backpack frame 11, and the control device 41 controls the drive of the electric motor 23 and from the battery pack 40 to the electric motor. 23 power supply is controlled. Other than these, the configuration is the same as that of the first embodiment described above.

  In the backpack type blower 10 configured as described above, the first and second electric motors 23A and 23B, which are heavy objects, are arranged as far as possible, and the battery pack 40 is placed below the first and second volute cases 21A and 21B. By being arranged on the side, the center of gravity G when viewed from the back of the back blower 10 is arranged below the rotation center shafts 22Aa and 22Ba of the first and second centrifugal fans 22A and 22B, and viewed from the side. The center of gravity G of the second volute case 21B is in front of the rear end position of the second volute case 21B on the rear side, particularly in this embodiment, the center of gravity G when viewed from the side is the center in the front-rear direction of the second volute case 21B. It was arranged in front of C. This prevents the shoulder strap 13 from being hung on the operator's shoulder so that the shoulder strap 13 is pulled to the rear side even when working with the shoulder-type blower 10 on the back, making it difficult for the operator to fall back and I was able to make it hard to get tired.

(Third embodiment)
Next, the back blower 10 of 3rd Embodiment is demonstrated using FIG.7 and FIG.8. 7 and 8, the description of the pair of left and right shoulder straps 13, the control device 41, and the cover 42 is omitted to mainly describe the arrangement of the blower units 20A and 20B and the battery pack 40. As with the back blower 10 of the second embodiment, the back blower 10 of the third embodiment is configured such that the blower unit 20 is composed of two blower units, the first and second blower units 20A and 20B. It is. In the third embodiment, the first and second blower units 20A and 20B are arranged side by side on the rear side of the back plate portion 12. Further, the first and second air blowing units 20A and 20B have a back plate portion 12 in order to balance the weight when a battery pack 40 (to be described later) is arranged vertically on the left side of the back plate portion 12 of the back frame 11. Are arranged side by side at a position shifted to the right from the center in the horizontal direction.

  As shown in FIG. 8, the first and second blower units 20A and 20B are integrally assembled with the first and second electric motors 23A and 23B on the front surfaces of the first and second volute cases 21A and 21B. The first and second centrifugal fans 22A and 22B are rotatably attached to the rotary shafts 23Aa and 23Ba of the first and second electric motors 23A and 23B in the first and second volute cases 21A and 21B, respectively. One unit. As shown in FIGS. 7 and 8, the first and second volute cases 21 </ b> A and 21 </ b> B have a spiral shape centering on a direction orthogonal (crossing) to the planar direction of the back plate portion 12. The first and second volute cases 21A, 21B are formed with air inlets 21Aa, 21Ba on the rear side, and cylindrical air blowing cylinder portions 21Ab, 21Bb extending outwardly on the right side extend outward. The blower ports 21Ac and 21Bc are formed at the tips of the blower cylinders 21Ab and 21Bb. In the third embodiment, a first connection pipe 24A is connected in communication between the blow cylinder 21Ab of the first volute case 21A arranged on the upper side and the blow pipe 30, and the second volute arranged on the lower side. A second connection pipe 24B is connected in communication between the blow cylinder portion 21Bb of the case 21B and the blow pipe 30.

  The back frame 11 of this embodiment does not include the pedestal portion 14 of the first and second embodiments, and four attachment portions 16 of the battery pack 40 are arranged side by side on the left side of the back plate portion 12. ing. A battery pack 40 is detachably attached to each attachment portion 16 so as to be slidable in the front-rear direction. The four battery packs 40 balance the weight in the left-right direction with the blower pipes 30 connected to the blower ports 21Ac and 21Bc of the first and second volute cases 21A and 21B at the right side of the backpack frame 11. The back plate 12 is attached to the left side. Other structures are the same as those in the third embodiment described above.

  In the back blower 10 configured as described above, the first and second electric motors 23 </ b> A and 23 </ b> B, which are heavy objects, are disposed immediately behind the back plate portion 12, and the battery pack 40 is immediately behind the back plate portion 12. By arranging it below the rotation center shaft 22Aa of the first centrifugal fan 22A on the rear side, the center of gravity G when viewed from the rear of the back blower 10 is below the rotation center shaft 22Aa of the first centrifugal fan 22A. The center of gravity G when viewed from the side is disposed in front of the rear end positions of the first and second volute cases 21A and 21B, particularly in this embodiment, the center of gravity G when viewed from the side. Is arranged in front of the front-rear direction centers of the first and second volute cases 21A, 21B. This prevents the shoulder strap 13 from being hung on the operator's shoulder so that the shoulder strap 13 is pulled to the rear side even when working with the shoulder-type blower 10 on the back, making it difficult for the operator to fall back and I was able to make it hard to get tired.

  In this embodiment, the battery pack 40 is vertically arranged on the left side of the back plate portion 12. However, the present invention is not limited to this, and the battery pack 40 is arranged below the back plate portion 12 (back plate). The upper surface of the pedestal portion 14 extending downward from the lower end of the portion 12 may be arranged side by side on the left and right. When arranged in this way, the position of the center of gravity of the back blower 10 can be further lowered, and fatigue can be reduced during work.

(Fourth embodiment)
Next, the back blower 10 according to the fourth embodiment will be described with reference to FIGS. 9 and 10. 9 and 10, the description of the pair of left and right shoulder straps 13, the control device 41, and the cover 42 is omitted in order to mainly describe the arrangement of the blower units 20 </ b> A and 20 </ b> B and the battery pack 40. The back blower 10 of the fourth embodiment has the first and second blower units 20A and 20B arranged side by side on the rear side of the back plate portion 12 in the same manner as the back blower 10 of the third embodiment. Yes. In the back blower 10 of the fourth embodiment, the lower second blower unit 20B is shifted to the rear side of the first blower unit 20A, thereby lowering the lower portion of the upper first volute case 21A and the lower second volute. Interference due to contact with the upper part of the case 21B is prevented, and the upper first blower unit 20A is arranged at a lower position than the back blower 10 of the third embodiment. In the fourth embodiment, since the first and second volute cases 21A, 21B are arranged on the rear side of the third embodiment, the battery pack 40 arranged on the left side of the back plate 12 is placed closer to the center. It can be placed close to each other. The battery pack 40 of the fourth embodiment is detachably attached so as to be slidable in the left-right direction. Other structures are the same as those in the third embodiment described above.

  In the back blower 10 configured as described above, the first and second electric motors 23A and 23B, which are heavy objects, are arranged on the rear side of the back plate portion 12, and three of the four battery packs 40 are disposed. By arranging the first centrifugal fan 22A on the lower side of the upper center centrifugal fan 22Aa immediately behind the back plate portion 12, the center of gravity G when viewed from the back of the back blower 10 is the first centrifugal fan 22A. The center of gravity G when viewed from the side is located on the front side of the rear end position of the second volute case 21B on the rear side, particularly in this embodiment, from the side. The center of gravity G when viewed is arranged in front of the center C in the front-rear direction of the first and second volute cases 21A, 21B. This prevents the shoulder strap 13 from being hung on the operator's shoulder so that the shoulder strap 13 is pulled to the rear side even when working with the shoulder-type blower 10 on the back, making it difficult for the operator to fall back and I was able to make it hard to get tired.

  In this embodiment as well, the battery pack 40 is vertically arranged on the left side of the back plate portion 12. However, the present invention is not limited to this, and the battery pack 40 is arranged below the back plate portion 12 (back plate). The upper surface of the pedestal portion 14 extending downward from the lower end of the portion 12 may be arranged side by side on the left and right. When arranged in this way, the position of the center of gravity of the back blower 10 can be further lowered, and fatigue can be reduced during work.

(Fifth embodiment)
Next, a back blower 10 according to a fifth embodiment will be described with reference to FIG. In FIG. 11, the description of the pair of left and right shoulder straps 13, the control device 41, and the cover 42 is omitted to mainly describe the arrangement of the blower units 20 </ b> A and 20 </ b> B. The back blower 10 of the fifth embodiment has the first and second blower units 20A and 20B arranged side by side on the rear side of the back plate 12 in the same manner as the back blower 10 of the third embodiment. Yes. In the back blower 10 of the fifth embodiment, the central axes of the first and second volute cases 21A, 21B, the rotational central axes 22Aa, 22Ba of the first and second centrifugal fans 22A, 22B, the first and second The axial directions of the rotation shafts 23Aa and 23Ba of the electric motors 23A and 23B are arranged so as to be inclined at 45 ° obliquely rearward. The first and second volute cases 21A and 21B have a spiral shape centering on a direction intersecting with the planar direction of the back plate portion 12 at 45 °. The rest is the same as in the third and fourth embodiments described above.

  In the back blower 10 configured as described above, the first and second electric motors 23 </ b> A and 23 </ b> B, which are heavy objects, are disposed on the rear side of the back plate portion 12, and are viewed from the back of the back blower 10. The center of gravity G is disposed below the rotation center shaft 22Aa of the first centrifugal fan 22A, and the center of gravity G when viewed from the side is in front of the rear end position of the second volute case 21B on the rear side. In particular, in this embodiment, the center of gravity G when viewed from the side is arranged in front of the center in the front-rear direction of the first and second volute cases 21A, 21B. This prevents the shoulder strap 13 from being hung on the operator's shoulder so that the shoulder strap 13 is pulled to the rear side even when working with the shoulder-type blower 10 on the back, making it difficult for the operator to fall back and I was able to make it hard to get tired.

  In this embodiment as well, the battery pack 40 is vertically arranged on the left side of the back plate portion 12. However, the present invention is not limited to this, and the battery pack 40 is arranged below the back plate portion 12 (back plate). The upper surface of the pedestal portion 14 extending downward from the lower end of the portion 12 may be arranged side by side on the left and right. When arranged in this way, the position of the center of gravity of the back blower 10 can be further lowered, and fatigue can be reduced during work.

  In each of the above embodiments, the first and second centrifugal fans 22A and 22B are attached to the output shafts (rotating shafts) of the electric motor 23 (23A and 23B), but the present invention is not limited to this. The first and second centrifugal fans 22A and 22B are attached to the rotation shafts that rotate the output shafts of the first and second electric motors 23 by a power transmission mechanism using, for example, a gear pair or a belt and a pulley. 23 may be driven by rotating a rotating shaft by a gear transmission mechanism and rotating the first and second centrifugal fans 22A and 22B by rotating the rotating shaft.

  In each of the embodiments described above, four battery packs for supplying electric power to the electric motor 23 (23A, 23B) are mounted on the back frame 11, but the present invention is not limited to this, and one or two battery packs are provided. One or more (a plurality of) battery packs may be used, and the same effects as described above can be obtained also in this way.

  DESCRIPTION OF SYMBOLS 10 ... Backside type blower working machine (backside type blower), 11 ... Backpack frame, 12 ... Back plate part, 13 ... Shoulder strap, 14 ... Base part, 21 ... Volute case, 21A ... Volute case (first volute case), 21B ... Volute case (second volute case), 22 ... Centrifugal fan, 22A ... Centrifugal fan (first centrifugal fan), 22B ... Centrifugal fan (second centrifugal fan), 23 ... Electric motor, 23A ... Electric motor (first Electric motor), 23B ... Electric motor (second electric motor), 40 ... Battery pack.

Claims (3)

A back frame that has at least a back plate portion along the operator's back, and the back plate portion is carried on the operator's back by a shoulder strap;
A volute case of a spiral shape that is mounted on the back frame on the back side of the back plate portion and centered on a direction intersecting the plane direction of the back plate portion,
A centrifugal fan rotatably supported in the volute case;
An electric motor assembled to the volute case to rotate the centrifugal fan;
A battery pack attached to the back frame and supplying power to the electric motor;
The center of gravity when viewed from behind is arranged below the rotation center axis of the centrifugal fan,
A back-loading type air blower characterized in that a center of gravity when viewed from the side is arranged in front of a rear end position of the volute case. The backpack type blower working machine according to claim 1,
A backpack-type blower working machine characterized in that a center of gravity when viewed from the side is arranged in front of a front-rear direction center of the volute case. The backpack type blower working machine according to claim 1 or 2,
The back frame includes a pedestal extending from the lower end of the back plate to the rear side;
A backpack type air blower characterized in that the battery pack is attached to the pedestal.

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